For the chemical equation given below, what is the amount of methane required to produce 72 g of water?
CH4(g)+2O2(g)→CO2(g)+2H2O(l)
32 g
Mass of water (H2O) to be produced = 72 g.
Gram molecular mass of a compound is the sum of gram atomic mass of all the constituent atoms.
Gram molecular mass of water = 18 g
No. of moles of H2O in 72 g
= Mass of waterGram molecular mass of water = 7218=4 mole
For 2 moles of H2O → 1 mole of methane is required
So, for 4 moles of H2O → 2 moles of methane is required.
Gram molecular mass of methane = 16 g
The required amount of methane =2×16=32 g.